Brain subvocalizes at 400-800 wpm. But that is only the subaudible parts. Combine with images, sounds, ‘pressures’, other senses, they combine to produce a unique language. Upon waking, I occasionally get access to mine, just for a few seconds or minutes, and I observe it passing by. It is a marvelous language that alas no function of my human body is fast enough to externalize.
So, I enjoy it while it happens and enjoy it when I get conscious memory of it again.